"It's my understanding the father was there nearby and the child was playing in the water, just a foot or so into the water, and the alligator came up. The father at some point struggled to try to get his son and was not successful and then alerted others to try to assist him in the process.

"At some point I am told the mother may also have entered the water. The parents diligently tried to get the child."

The child was attacked at Seven Seas Lagoon by Disney's Grand Floridian Hotel. Demings said that there are signs warning against swimming in the water.

"Disney, I will tell, is completely co-operating with this investigation," he added. "Their priority is on recovering the child and assisting this family tonight.

"Hopefully we will successfully recover the child before daylight. We're not leaving without the child."

A Disney spokesperson said: "Everyone here at the Walt Disney World resort is devastated by this tragic accident. Our thoughts are with the family. We are helping the family and doing everything we can to assist law enforcement."